New test methods added.
Bug in increaseEscapeState() fixed; depending on whether the phantom
object is a sub-object or not, the correct constructor is called.
High level method getArgumentAtIndex() added.
Continued development (publishEscapedArgs() added).
removeLocalGraph() added.
Ast node for ACONST_Null added. When an ACONST_NULL instruction is
executed, a reference to the special null object is pushed onto the op
stack.
New test methods added.
Method getFieldOf() moved from ConnectionGraph to ObjectNodes.
In applyMethodSummary(), transferFieldEdges() added. For that purpose,
also mapsTo() added.
Field objectNodes renamed argEscapeObjects.
Test method added.
MethodSummary now deals with the method result as well; it is modelled
as a reference node plus a set of points-to edges.